1 /*
2 ********************************************************************************
3 *   Copyright (C) 1997-2014, International Business Machines
4 *   Corporation and others.  All Rights Reserved.
5 ********************************************************************************
6 *
7 * File CALENDAR.H
8 *
9 * Modification History:
10 *
11 *   Date        Name        Description
12 *   04/22/97    aliu        Expanded and corrected comments and other header
13 *                           contents.
14 *   05/01/97    aliu        Made equals(), before(), after() arguments const.
15 *   05/20/97    aliu        Replaced fAreFieldsSet with fAreFieldsInSync and
16 *                           fAreAllFieldsSet.
17 *   07/27/98    stephen     Sync up with JDK 1.2
18 *   11/15/99    weiv        added YEAR_WOY and DOW_LOCAL
19 *                           to EDateFields
20 *    8/19/2002  srl         Removed Javaisms
21 *   11/07/2003  srl         Update, clean up documentation.
22 ********************************************************************************
23 */
24 
25 #ifndef CALENDAR_H
26 #define CALENDAR_H
27 
28 #include "unicode/utypes.h"
29 
30 /**
31  * \file
32  * \brief C++ API: Calendar object
33  */
34 #if !UCONFIG_NO_FORMATTING
35 
36 #include "unicode/uobject.h"
37 #include "unicode/locid.h"
38 #include "unicode/timezone.h"
39 #include "unicode/ucal.h"
40 #include "unicode/umisc.h"
41 
42 U_NAMESPACE_BEGIN
43 
44 class ICUServiceFactory;
45 
46 /**
47  * @internal
48  */
49 typedef int32_t UFieldResolutionTable[12][8];
50 
51 class BasicTimeZone;
52 /**
53  * <code>Calendar</code> is an abstract base class for converting between
54  * a <code>UDate</code> object and a set of integer fields such as
55  * <code>YEAR</code>, <code>MONTH</code>, <code>DAY</code>, <code>HOUR</code>,
56  * and so on. (A <code>UDate</code> object represents a specific instant in
57  * time with millisecond precision. See UDate
58  * for information about the <code>UDate</code> class.)
59  *
60  * <p>
61  * Subclasses of <code>Calendar</code> interpret a <code>UDate</code>
62  * according to the rules of a specific calendar system.
63  * The most commonly used subclass of <code>Calendar</code> is
64  * <code>GregorianCalendar</code>. Other subclasses could represent
65  * the various types of lunar calendars in use in many parts of the world.
66  *
67  * <p>
68  * <b>NOTE</b>: (ICU 2.6) The subclass interface should be considered unstable
69  * - it WILL change.
70  *
71  * <p>
72  * Like other locale-sensitive classes, <code>Calendar</code> provides a
73  * static method, <code>createInstance</code>, for getting a generally useful
74  * object of this type. <code>Calendar</code>'s <code>createInstance</code> method
75  * returns the appropriate <code>Calendar</code> subclass whose
76  * time fields have been initialized with the current date and time:
77  * \htmlonly<blockquote>\endhtmlonly
78  * <pre>
79  * Calendar *rightNow = Calendar::createInstance(errCode);
80  * </pre>
81  * \htmlonly</blockquote>\endhtmlonly
82  *
83  * <p>
84  * A <code>Calendar</code> object can produce all the time field values
85  * needed to implement the date-time formatting for a particular language
86  * and calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
87  *
88  * <p>
89  * When computing a <code>UDate</code> from time fields, some special circumstances
90  * may arise: there may be insufficient information to compute the
91  * <code>UDate</code> (such as only year and month but no day in the month),
92  * there may be inconsistent information (such as "Tuesday, July 15, 1996"
93  * -- July 15, 1996 is actually a Monday), or the input time might be ambiguous
94  * because of time zone transition.
95  *
96  * <p>
97  * <strong>Insufficient information.</strong> The calendar will use default
98  * information to specify the missing fields. This may vary by calendar; for
99  * the Gregorian calendar, the default for a field is the same as that of the
100  * start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.
101  *
102  * <p>
103  * <strong>Inconsistent information.</strong> If fields conflict, the calendar
104  * will give preference to fields set more recently. For example, when
105  * determining the day, the calendar will look for one of the following
106  * combinations of fields.  The most recent combination, as determined by the
107  * most recently set single field, will be used.
108  *
109  * \htmlonly<blockquote>\endhtmlonly
110  * <pre>
111  * MONTH + DAY_OF_MONTH
112  * MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
113  * MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
114  * DAY_OF_YEAR
115  * DAY_OF_WEEK + WEEK_OF_YEAR
116  * </pre>
117  * \htmlonly</blockquote>\endhtmlonly
118  *
119  * For the time of day:
120  *
121  * \htmlonly<blockquote>\endhtmlonly
122  * <pre>
123  * HOUR_OF_DAY
124  * AM_PM + HOUR
125  * </pre>
126  * \htmlonly</blockquote>\endhtmlonly
127  *
128  * <p>
129  * <strong>Ambiguous Wall Clock Time.</strong> When time offset from UTC has
130  * changed, it produces an ambiguous time slot around the transition. For example,
131  * many US locations observe daylight saving time. On the date switching to daylight
132  * saving time in US, wall clock time jumps from 12:59 AM (standard) to 2:00 AM
133  * (daylight). Therefore, wall clock time from 1:00 AM to 1:59 AM do not exist on
134  * the date. When the input wall time fall into this missing time slot, the ICU
135  * Calendar resolves the time using the UTC offset before the transition by default.
136  * In this example, 1:30 AM is interpreted as 1:30 AM standard time (non-exist),
137  * so the final result will be 2:30 AM daylight time.
138  *
139  * <p>On the date switching back to standard time, wall clock time is moved back one
140  * hour at 2:00 AM. So wall clock time from 1:00 AM to 1:59 AM occur twice. In this
141  * case, the ICU Calendar resolves the time using the UTC offset after the transition
142  * by default. For example, 1:30 AM on the date is resolved as 1:30 AM standard time.
143  *
144  * <p>Ambiguous wall clock time resolution behaviors can be customized by Calendar APIs
145  * {@link #setRepeatedWallTimeOption} and {@link #setSkippedWallTimeOption}.
146  * These methods are available in ICU 49 or later versions.
147  *
148  * <p>
149  * <strong>Note:</strong> for some non-Gregorian calendars, different
150  * fields may be necessary for complete disambiguation. For example, a full
151  * specification of the historial Arabic astronomical calendar requires year,
152  * month, day-of-month <em>and</em> day-of-week in some cases.
153  *
154  * <p>
155  * <strong>Note:</strong> There are certain possible ambiguities in
156  * interpretation of certain singular times, which are resolved in the
157  * following ways:
158  * <ol>
159  *     <li> 24:00:00 "belongs" to the following day. That is,
160  *          23:59 on Dec 31, 1969 &lt; 24:00 on Jan 1, 1970 &lt; 24:01:00 on Jan 1, 1970
161  *
162  *     <li> Although historically not precise, midnight also belongs to "am",
163  *          and noon belongs to "pm", so on the same day,
164  *          12:00 am (midnight) &lt; 12:01 am, and 12:00 pm (noon) &lt; 12:01 pm
165  * </ol>
166  *
167  * <p>
168  * The date or time format strings are not part of the definition of a
169  * calendar, as those must be modifiable or overridable by the user at
170  * runtime. Use {@link DateFormat}
171  * to format dates.
172  *
173  * <p>
174  * <code>Calendar</code> provides an API for field "rolling", where fields
175  * can be incremented or decremented, but wrap around. For example, rolling the
176  * month up in the date <code>December 12, <b>1996</b></code> results in
177  * <code>January 12, <b>1996</b></code>.
178  *
179  * <p>
180  * <code>Calendar</code> also provides a date arithmetic function for
181  * adding the specified (signed) amount of time to a particular time field.
182  * For example, subtracting 5 days from the date <code>September 12, 1996</code>
183  * results in <code>September 7, 1996</code>.
184  *
185  * <p><big><b>Supported range</b></big>
186  *
187  * <p>The allowable range of <code>Calendar</code> has been
188  * narrowed. <code>GregorianCalendar</code> used to attempt to support
189  * the range of dates with millisecond values from
190  * <code>Long.MIN_VALUE</code> to <code>Long.MAX_VALUE</code>.
191  * The new <code>Calendar</code> protocol specifies the
192  * maximum range of supportable dates as those having Julian day numbers
193  * of <code>-0x7F000000</code> to <code>+0x7F000000</code>. This
194  * corresponds to years from ~5,800,000 BCE to ~5,800,000 CE. Programmers
195  * should use the protected constants in <code>Calendar</code> to
196  * specify an extremely early or extremely late date.</p>
197  *
198  * @stable ICU 2.0
199  */
200 class U_I18N_API Calendar : public UObject {
201 public:
202 
203     /**
204      * Field IDs for date and time. Used to specify date/time fields. ERA is calendar
205      * specific. Example ranges given are for illustration only; see specific Calendar
206      * subclasses for actual ranges.
207      * @deprecated ICU 2.6. Use C enum UCalendarDateFields defined in ucal.h
208      */
209     enum EDateFields {
210 #ifndef U_HIDE_DEPRECATED_API
211 /*
212  * ERA may be defined on other platforms. To avoid any potential problems undefined it here.
213  */
214 #ifdef ERA
215 #undef ERA
216 #endif
217         ERA,                  // Example: 0..1
218         YEAR,                 // Example: 1..big number
219         MONTH,                // Example: 0..11
220         WEEK_OF_YEAR,         // Example: 1..53
221         WEEK_OF_MONTH,        // Example: 1..4
222         DATE,                 // Example: 1..31
223         DAY_OF_YEAR,          // Example: 1..365
224         DAY_OF_WEEK,          // Example: 1..7
225         DAY_OF_WEEK_IN_MONTH, // Example: 1..4, may be specified as -1
226         AM_PM,                // Example: 0..1
227         HOUR,                 // Example: 0..11
228         HOUR_OF_DAY,          // Example: 0..23
229         MINUTE,               // Example: 0..59
230         SECOND,               // Example: 0..59
231         MILLISECOND,          // Example: 0..999
232         ZONE_OFFSET,          // Example: -12*U_MILLIS_PER_HOUR..12*U_MILLIS_PER_HOUR
233         DST_OFFSET,           // Example: 0 or U_MILLIS_PER_HOUR
234         YEAR_WOY,             // 'Y' Example: 1..big number - Year of Week of Year
235         DOW_LOCAL,            // 'e' Example: 1..7 - Day of Week / Localized
236 
237         EXTENDED_YEAR,
238         JULIAN_DAY,
239         MILLISECONDS_IN_DAY,
240         IS_LEAP_MONTH,
241 
242         FIELD_COUNT = UCAL_FIELD_COUNT // See ucal.h for other fields.
243 #endif /* U_HIDE_DEPRECATED_API */
244     };
245 
246 #ifndef U_HIDE_DEPRECATED_API
247     /**
248      * Useful constant for days of week. Note: Calendar day-of-week is 1-based. Clients
249      * who create locale resources for the field of first-day-of-week should be aware of
250      * this. For instance, in US locale, first-day-of-week is set to 1, i.e., SUNDAY.
251      * @deprecated ICU 2.6. Use C enum UCalendarDaysOfWeek defined in ucal.h
252      */
253     enum EDaysOfWeek {
254         SUNDAY = 1,
255         MONDAY,
256         TUESDAY,
257         WEDNESDAY,
258         THURSDAY,
259         FRIDAY,
260         SATURDAY
261     };
262 
263     /**
264      * Useful constants for month. Note: Calendar month is 0-based.
265      * @deprecated ICU 2.6. Use C enum UCalendarMonths defined in ucal.h
266      */
267     enum EMonths {
268         JANUARY,
269         FEBRUARY,
270         MARCH,
271         APRIL,
272         MAY,
273         JUNE,
274         JULY,
275         AUGUST,
276         SEPTEMBER,
277         OCTOBER,
278         NOVEMBER,
279         DECEMBER,
280         UNDECIMBER
281     };
282 
283     /**
284      * Useful constants for hour in 12-hour clock. Used in GregorianCalendar.
285      * @deprecated ICU 2.6. Use C enum UCalendarAMPMs defined in ucal.h
286      */
287     enum EAmpm {
288         AM,
289         PM
290     };
291 #endif  /* U_HIDE_DEPRECATED_API */
292 
293     /**
294      * destructor
295      * @stable ICU 2.0
296      */
297     virtual ~Calendar();
298 
299     /**
300      * Create and return a polymorphic copy of this calendar.
301      *
302      * @return    a polymorphic copy of this calendar.
303      * @stable ICU 2.0
304      */
305     virtual Calendar* clone(void) const = 0;
306 
307     /**
308      * Creates a Calendar using the default timezone and locale. Clients are responsible
309      * for deleting the object returned.
310      *
311      * @param success  Indicates the success/failure of Calendar creation. Filled in
312      *                 with U_ZERO_ERROR if created successfully, set to a failure result
313      *                 otherwise. U_MISSING_RESOURCE_ERROR will be returned if the resource data
314      *                 requests a calendar type which has not been installed.
315      * @return         A Calendar if created successfully. NULL otherwise.
316      * @stable ICU 2.0
317      */
318     static Calendar* U_EXPORT2 createInstance(UErrorCode& success);
319 
320     /**
321      * Creates a Calendar using the given timezone and the default locale.
322      * The Calendar takes ownership of zoneToAdopt; the
323      * client must not delete it.
324      *
325      * @param zoneToAdopt  The given timezone to be adopted.
326      * @param success      Indicates the success/failure of Calendar creation. Filled in
327      *                     with U_ZERO_ERROR if created successfully, set to a failure result
328      *                     otherwise.
329      * @return             A Calendar if created successfully. NULL otherwise.
330      * @stable ICU 2.0
331      */
332     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, UErrorCode& success);
333 
334     /**
335      * Creates a Calendar using the given timezone and the default locale.  The TimeZone
336      * is _not_ adopted; the client is still responsible for deleting it.
337      *
338      * @param zone  The timezone.
339      * @param success      Indicates the success/failure of Calendar creation. Filled in
340      *                     with U_ZERO_ERROR if created successfully, set to a failure result
341      *                     otherwise.
342      * @return             A Calendar if created successfully. NULL otherwise.
343      * @stable ICU 2.0
344      */
345     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, UErrorCode& success);
346 
347     /**
348      * Creates a Calendar using the default timezone and the given locale.
349      *
350      * @param aLocale  The given locale.
351      * @param success  Indicates the success/failure of Calendar creation. Filled in
352      *                 with U_ZERO_ERROR if created successfully, set to a failure result
353      *                 otherwise.
354      * @return         A Calendar if created successfully. NULL otherwise.
355      * @stable ICU 2.0
356      */
357     static Calendar* U_EXPORT2 createInstance(const Locale& aLocale, UErrorCode& success);
358 
359     /**
360      * Creates a Calendar using the given timezone and given locale.
361      * The Calendar takes ownership of zoneToAdopt; the
362      * client must not delete it.
363      *
364      * @param zoneToAdopt  The given timezone to be adopted.
365      * @param aLocale      The given locale.
366      * @param success      Indicates the success/failure of Calendar creation. Filled in
367      *                     with U_ZERO_ERROR if created successfully, set to a failure result
368      *                     otherwise.
369      * @return             A Calendar if created successfully. NULL otherwise.
370      * @stable ICU 2.0
371      */
372     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, const Locale& aLocale, UErrorCode& success);
373 
374     /**
375      * Gets a Calendar using the given timezone and given locale.  The TimeZone
376      * is _not_ adopted; the client is still responsible for deleting it.
377      *
378      * @param zone         The given timezone.
379      * @param aLocale      The given locale.
380      * @param success      Indicates the success/failure of Calendar creation. Filled in
381      *                     with U_ZERO_ERROR if created successfully, set to a failure result
382      *                     otherwise.
383      * @return             A Calendar if created successfully. NULL otherwise.
384      * @stable ICU 2.0
385      */
386     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
387 
388     /**
389      * Returns a list of the locales for which Calendars are installed.
390      *
391      * @param count  Number of locales returned.
392      * @return       An array of Locale objects representing the set of locales for which
393      *               Calendars are installed.  The system retains ownership of this list;
394      *               the caller must NOT delete it. Does not include user-registered Calendars.
395      * @stable ICU 2.0
396      */
397     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
398 
399 
400     /**
401      * Given a key and a locale, returns an array of string values in a preferred
402      * order that would make a difference. These are all and only those values where
403      * the open (creation) of the service with the locale formed from the input locale
404      * plus input keyword and that value has different behavior than creation with the
405      * input locale alone.
406      * @param key           one of the keys supported by this service.  For now, only
407      *                      "calendar" is supported.
408      * @param locale        the locale
409      * @param commonlyUsed  if set to true it will return only commonly used values
410      *                      with the given locale in preferred order.  Otherwise,
411      *                      it will return all the available values for the locale.
412      * @param status        ICU Error Code
413      * @return a string enumeration over keyword values for the given key and the locale.
414      * @stable ICU 4.2
415      */
416     static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* key,
417                     const Locale& locale, UBool commonlyUsed, UErrorCode& status);
418 
419     /**
420      * Returns the current UTC (GMT) time measured in milliseconds since 0:00:00 on 1/1/70
421      * (derived from the system time).
422      *
423      * @return   The current UTC time in milliseconds.
424      * @stable ICU 2.0
425      */
426     static UDate U_EXPORT2 getNow(void);
427 
428     /**
429      * Gets this Calendar's time as milliseconds. May involve recalculation of time due
430      * to previous calls to set time field values. The time specified is non-local UTC
431      * (GMT) time. Although this method is const, this object may actually be changed
432      * (semantically const).
433      *
434      * @param status  Output param set to success/failure code on exit. If any value
435      *                previously set in the time field is invalid or restricted by
436      *                leniency, this will be set to an error status.
437      * @return        The current time in UTC (GMT) time, or zero if the operation
438      *                failed.
439      * @stable ICU 2.0
440      */
getTime(UErrorCode & status)441     inline UDate getTime(UErrorCode& status) const { return getTimeInMillis(status); }
442 
443     /**
444      * Sets this Calendar's current time with the given UDate. The time specified should
445      * be in non-local UTC (GMT) time.
446      *
447      * @param date  The given UDate in UTC (GMT) time.
448      * @param status  Output param set to success/failure code on exit. If any value
449      *                set in the time field is invalid or restricted by
450      *                leniency, this will be set to an error status.
451      * @stable ICU 2.0
452      */
setTime(UDate date,UErrorCode & status)453     inline void setTime(UDate date, UErrorCode& status) { setTimeInMillis(date, status); }
454 
455     /**
456      * Compares the equality of two Calendar objects. Objects of different subclasses
457      * are considered unequal. This comparison is very exacting; two Calendar objects
458      * must be in exactly the same state to be considered equal. To compare based on the
459      * represented time, use equals() instead.
460      *
461      * @param that  The Calendar object to be compared with.
462      * @return      True if the given Calendar is the same as this Calendar; false
463      *              otherwise.
464      * @stable ICU 2.0
465      */
466     virtual UBool operator==(const Calendar& that) const;
467 
468     /**
469      * Compares the inequality of two Calendar objects.
470      *
471      * @param that  The Calendar object to be compared with.
472      * @return      True if the given Calendar is not the same as this Calendar; false
473      *              otherwise.
474      * @stable ICU 2.0
475      */
476     UBool operator!=(const Calendar& that) const {return !operator==(that);}
477 
478     /**
479      * Returns TRUE if the given Calendar object is equivalent to this
480      * one.  An equivalent Calendar will behave exactly as this one
481      * does, but it may be set to a different time.  By contrast, for
482      * the operator==() method to return TRUE, the other Calendar must
483      * be set to the same time.
484      *
485      * @param other the Calendar to be compared with this Calendar
486      * @stable ICU 2.4
487      */
488     virtual UBool isEquivalentTo(const Calendar& other) const;
489 
490     /**
491      * Compares the Calendar time, whereas Calendar::operator== compares the equality of
492      * Calendar objects.
493      *
494      * @param when    The Calendar to be compared with this Calendar. Although this is a
495      *                const parameter, the object may be modified physically
496      *                (semantically const).
497      * @param status  Output param set to success/failure code on exit. If any value
498      *                previously set in the time field is invalid or restricted by
499      *                leniency, this will be set to an error status.
500      * @return        True if the current time of this Calendar is equal to the time of
501      *                Calendar when; false otherwise.
502      * @stable ICU 2.0
503      */
504     UBool equals(const Calendar& when, UErrorCode& status) const;
505 
506     /**
507      * Returns true if this Calendar's current time is before "when"'s current time.
508      *
509      * @param when    The Calendar to be compared with this Calendar. Although this is a
510      *                const parameter, the object may be modified physically
511      *                (semantically const).
512      * @param status  Output param set to success/failure code on exit. If any value
513      *                previously set in the time field is invalid or restricted by
514      *                leniency, this will be set to an error status.
515      * @return        True if the current time of this Calendar is before the time of
516      *                Calendar when; false otherwise.
517      * @stable ICU 2.0
518      */
519     UBool before(const Calendar& when, UErrorCode& status) const;
520 
521     /**
522      * Returns true if this Calendar's current time is after "when"'s current time.
523      *
524      * @param when    The Calendar to be compared with this Calendar. Although this is a
525      *                const parameter, the object may be modified physically
526      *                (semantically const).
527      * @param status  Output param set to success/failure code on exit. If any value
528      *                previously set in the time field is invalid or restricted by
529      *                leniency, this will be set to an error status.
530      * @return        True if the current time of this Calendar is after the time of
531      *                Calendar when; false otherwise.
532      * @stable ICU 2.0
533      */
534     UBool after(const Calendar& when, UErrorCode& status) const;
535 
536     /**
537      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
538      * time field, based on the calendar's rules. For example, to subtract 5 days from
539      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
540      * the month or Calendar::MONTH field, other fields like date might conflict and
541      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
542      * in 02/29/96.
543      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
544      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
545      * the numeric value of the field itself).
546      *
547      * @param field   Specifies which date field to modify.
548      * @param amount  The amount of time to be added to the field, in the natural unit
549      *                for that field (e.g., days for the day fields, hours for the hour
550      *                field.)
551      * @param status  Output param set to success/failure code on exit. If any value
552      *                previously set in the time field is invalid or restricted by
553      *                leniency, this will be set to an error status.
554      * @deprecated ICU 2.6. use add(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
555      */
556     virtual void add(EDateFields field, int32_t amount, UErrorCode& status);
557 
558     /**
559      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
560      * time field, based on the calendar's rules. For example, to subtract 5 days from
561      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
562      * the month or Calendar::MONTH field, other fields like date might conflict and
563      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
564      * in 02/29/96.
565      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
566      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
567      * the numeric value of the field itself).
568      *
569      * @param field   Specifies which date field to modify.
570      * @param amount  The amount of time to be added to the field, in the natural unit
571      *                for that field (e.g., days for the day fields, hours for the hour
572      *                field.)
573      * @param status  Output param set to success/failure code on exit. If any value
574      *                previously set in the time field is invalid or restricted by
575      *                leniency, this will be set to an error status.
576      * @stable ICU 2.6.
577      */
578     virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode& status);
579 
580 #ifndef U_HIDE_DEPRECATED_API
581     /**
582      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
583      * time field. For example, to roll the current date up by one day, call
584      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
585      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
586      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
587      * Calendar::MONTH field, other fields like date might conflict and, need to be
588      * changed. For instance, rolling the month up on the date 01/31/96 will result in
589      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
590      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
591      * starting with 100 BC and rolling the year up results in 99 BC.
592      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
593      * most eras in the Japanese calendar) then rolling the year past either limit of the
594      * era will cause the year to wrap around. When eras only have a limit at one end,
595      * then attempting to roll the year past that limit will result in pinning the year
596      * at that limit. Note that for most calendars in which era 0 years move forward in
597      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
598      * result in negative years for era 0 (that is the only way to represent years before
599      * the calendar epoch).
600      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
601      * hour value in the range between 0 and 23, which is zero-based.
602      * <P>
603      * NOTE: Do not use this method -- use roll(EDateFields, int, UErrorCode&) instead.
604      *
605      * @param field   The time field.
606      * @param up      Indicates if the value of the specified time field is to be rolled
607      *                up or rolled down. Use true if rolling up, false otherwise.
608      * @param status  Output param set to success/failure code on exit. If any value
609      *                previously set in the time field is invalid or restricted by
610      *                leniency, this will be set to an error status.
611      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, UBool up, UErrorCode& status) instead.
612      */
613     inline void roll(EDateFields field, UBool up, UErrorCode& status);
614 #endif  /* U_HIDE_DEPRECATED_API */
615 
616     /**
617      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
618      * time field. For example, to roll the current date up by one day, call
619      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
620      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
621      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
622      * Calendar::MONTH field, other fields like date might conflict and, need to be
623      * changed. For instance, rolling the month up on the date 01/31/96 will result in
624      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
625      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
626      * starting with 100 BC and rolling the year up results in 99 BC.
627      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
628      * most eras in the Japanese calendar) then rolling the year past either limit of the
629      * era will cause the year to wrap around. When eras only have a limit at one end,
630      * then attempting to roll the year past that limit will result in pinning the year
631      * at that limit. Note that for most calendars in which era 0 years move forward in
632      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
633      * result in negative years for era 0 (that is the only way to represent years before
634      * the calendar epoch).
635      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
636      * hour value in the range between 0 and 23, which is zero-based.
637      * <P>
638      * NOTE: Do not use this method -- use roll(UCalendarDateFields, int, UErrorCode&) instead.
639      *
640      * @param field   The time field.
641      * @param up      Indicates if the value of the specified time field is to be rolled
642      *                up or rolled down. Use true if rolling up, false otherwise.
643      * @param status  Output param set to success/failure code on exit. If any value
644      *                previously set in the time field is invalid or restricted by
645      *                leniency, this will be set to an error status.
646      * @stable ICU 2.6.
647      */
648     inline void roll(UCalendarDateFields field, UBool up, UErrorCode& status);
649 
650     /**
651      * Time Field Rolling function. Rolls by the given amount on the given
652      * time field. For example, to roll the current date up by one day, call
653      * roll(Calendar::DATE, +1, status). When rolling on the month or
654      * Calendar::MONTH field, other fields like date might conflict and, need to be
655      * changed. For instance, rolling the month up on the date 01/31/96 will result in
656      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
657      * the limit of the field is reached, in which case it may pin or wrap), so for
658      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
659      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
660      * most eras in the Japanese calendar) then rolling the year past either limit of the
661      * era will cause the year to wrap around. When eras only have a limit at one end,
662      * then attempting to roll the year past that limit will result in pinning the year
663      * at that limit. Note that for most calendars in which era 0 years move forward in
664      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
665      * result in negative years for era 0 (that is the only way to represent years before
666      * the calendar epoch).
667      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
668      * hour value in the range between 0 and 23, which is zero-based.
669      * <P>
670      * The only difference between roll() and add() is that roll() does not change
671      * the value of more significant fields when it reaches the minimum or maximum
672      * of its range, whereas add() does.
673      *
674      * @param field   The time field.
675      * @param amount  Indicates amount to roll.
676      * @param status  Output param set to success/failure code on exit. If any value
677      *                previously set in the time field is invalid, this will be set to
678      *                an error status.
679      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
680      */
681     virtual void roll(EDateFields field, int32_t amount, UErrorCode& status);
682 
683     /**
684      * Time Field Rolling function. Rolls by the given amount on the given
685      * time field. For example, to roll the current date up by one day, call
686      * roll(Calendar::DATE, +1, status). When rolling on the month or
687      * Calendar::MONTH field, other fields like date might conflict and, need to be
688      * changed. For instance, rolling the month up on the date 01/31/96 will result in
689      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
690      * the limit of the field is reached, in which case it may pin or wrap), so for
691      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
692      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
693      * most eras in the Japanese calendar) then rolling the year past either limit of the
694      * era will cause the year to wrap around. When eras only have a limit at one end,
695      * then attempting to roll the year past that limit will result in pinning the year
696      * at that limit. Note that for most calendars in which era 0 years move forward in
697      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
698      * result in negative years for era 0 (that is the only way to represent years before
699      * the calendar epoch).
700      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
701      * hour value in the range between 0 and 23, which is zero-based.
702      * <P>
703      * The only difference between roll() and add() is that roll() does not change
704      * the value of more significant fields when it reaches the minimum or maximum
705      * of its range, whereas add() does.
706      *
707      * @param field   The time field.
708      * @param amount  Indicates amount to roll.
709      * @param status  Output param set to success/failure code on exit. If any value
710      *                previously set in the time field is invalid, this will be set to
711      *                an error status.
712      * @stable ICU 2.6.
713      */
714     virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode& status);
715 
716     /**
717      * Return the difference between the given time and the time this
718      * calendar object is set to.  If this calendar is set
719      * <em>before</em> the given time, the returned value will be
720      * positive.  If this calendar is set <em>after</em> the given
721      * time, the returned value will be negative.  The
722      * <code>field</code> parameter specifies the units of the return
723      * value.  For example, if <code>fieldDifference(when,
724      * Calendar::MONTH)</code> returns 3, then this calendar is set to
725      * 3 months before <code>when</code>, and possibly some addition
726      * time less than one month.
727      *
728      * <p>As a side effect of this call, this calendar is advanced
729      * toward <code>when</code> by the given amount.  That is, calling
730      * this method has the side effect of calling <code>add(field,
731      * n)</code>, where <code>n</code> is the return value.
732      *
733      * <p>Usage: To use this method, call it first with the largest
734      * field of interest, then with progressively smaller fields.  For
735      * example:
736      *
737      * <pre>
738      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
739      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
740      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
741      *
742      * computes the difference between <code>cal</code> and
743      * <code>when</code> in years, months, and days.
744      *
745      * <p>Note: <code>fieldDifference()</code> is
746      * <em>asymmetrical</em>.  That is, in the following code:
747      *
748      * <pre>
749      * cal->setTime(date1, err);
750      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
751      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
752      * cal->setTime(date2, err);
753      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
754      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
755      *
756      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
757      * However, this is not generally the case, because of
758      * irregularities in the underlying calendar system (e.g., the
759      * Gregorian calendar has a varying number of days per month).
760      *
761      * @param when the date to compare this calendar's time to
762      * @param field the field in which to compute the result
763      * @param status  Output param set to success/failure code on exit. If any value
764      *                previously set in the time field is invalid, this will be set to
765      *                an error status.
766      * @return the difference, either positive or negative, between
767      * this calendar's time and <code>when</code>, in terms of
768      * <code>field</code>.
769      * @deprecated ICU 2.6. Use fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status).
770      */
771     virtual int32_t fieldDifference(UDate when, EDateFields field, UErrorCode& status);
772 
773     /**
774      * Return the difference between the given time and the time this
775      * calendar object is set to.  If this calendar is set
776      * <em>before</em> the given time, the returned value will be
777      * positive.  If this calendar is set <em>after</em> the given
778      * time, the returned value will be negative.  The
779      * <code>field</code> parameter specifies the units of the return
780      * value.  For example, if <code>fieldDifference(when,
781      * Calendar::MONTH)</code> returns 3, then this calendar is set to
782      * 3 months before <code>when</code>, and possibly some addition
783      * time less than one month.
784      *
785      * <p>As a side effect of this call, this calendar is advanced
786      * toward <code>when</code> by the given amount.  That is, calling
787      * this method has the side effect of calling <code>add(field,
788      * n)</code>, where <code>n</code> is the return value.
789      *
790      * <p>Usage: To use this method, call it first with the largest
791      * field of interest, then with progressively smaller fields.  For
792      * example:
793      *
794      * <pre>
795      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
796      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
797      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
798      *
799      * computes the difference between <code>cal</code> and
800      * <code>when</code> in years, months, and days.
801      *
802      * <p>Note: <code>fieldDifference()</code> is
803      * <em>asymmetrical</em>.  That is, in the following code:
804      *
805      * <pre>
806      * cal->setTime(date1, err);
807      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
808      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
809      * cal->setTime(date2, err);
810      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
811      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
812      *
813      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
814      * However, this is not generally the case, because of
815      * irregularities in the underlying calendar system (e.g., the
816      * Gregorian calendar has a varying number of days per month).
817      *
818      * @param when the date to compare this calendar's time to
819      * @param field the field in which to compute the result
820      * @param status  Output param set to success/failure code on exit. If any value
821      *                previously set in the time field is invalid, this will be set to
822      *                an error status.
823      * @return the difference, either positive or negative, between
824      * this calendar's time and <code>when</code>, in terms of
825      * <code>field</code>.
826      * @stable ICU 2.6.
827      */
828     virtual int32_t fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status);
829 
830     /**
831      * Sets the calendar's time zone to be the one passed in. The Calendar takes ownership
832      * of the TimeZone; the caller is no longer responsible for deleting it.  If the
833      * given time zone is NULL, this function has no effect.
834      *
835      * @param value  The given time zone.
836      * @stable ICU 2.0
837      */
838     void adoptTimeZone(TimeZone* value);
839 
840     /**
841      * Sets the calendar's time zone to be the same as the one passed in. The TimeZone
842      * passed in is _not_ adopted; the client is still responsible for deleting it.
843      *
844      * @param zone  The given time zone.
845      * @stable ICU 2.0
846      */
847     void setTimeZone(const TimeZone& zone);
848 
849     /**
850      * Returns a reference to the time zone owned by this calendar. The returned reference
851      * is only valid until clients make another call to adoptTimeZone or setTimeZone,
852      * or this Calendar is destroyed.
853      *
854      * @return   The time zone object associated with this calendar.
855      * @stable ICU 2.0
856      */
857     const TimeZone& getTimeZone(void) const;
858 
859     /**
860      * Returns the time zone owned by this calendar. The caller owns the returned object
861      * and must delete it when done.  After this call, the new time zone associated
862      * with this Calendar is the default TimeZone as returned by TimeZone::createDefault().
863      *
864      * @return   The time zone object which was associated with this calendar.
865      * @stable ICU 2.0
866      */
867     TimeZone* orphanTimeZone(void);
868 
869     /**
870      * Queries if the current date for this Calendar is in Daylight Savings Time.
871      *
872      * @param status Fill-in parameter which receives the status of this operation.
873      * @return   True if the current date for this Calendar is in Daylight Savings Time,
874      *           false, otherwise.
875      * @stable ICU 2.0
876      */
877     virtual UBool inDaylightTime(UErrorCode& status) const = 0;
878 
879     /**
880      * Specifies whether or not date/time interpretation is to be lenient. With lenient
881      * interpretation, a date such as "February 942, 1996" will be treated as being
882      * equivalent to the 941st day after February 1, 1996. With strict interpretation,
883      * such dates will cause an error when computing time from the time field values
884      * representing the dates.
885      *
886      * @param lenient  True specifies date/time interpretation to be lenient.
887      *
888      * @see            DateFormat#setLenient
889      * @stable ICU 2.0
890      */
891     void setLenient(UBool lenient);
892 
893     /**
894      * Tells whether date/time interpretation is to be lenient.
895      *
896      * @return   True tells that date/time interpretation is to be lenient.
897      * @stable ICU 2.0
898      */
899     UBool isLenient(void) const;
900 
901     /**
902      * Sets the behavior for handling wall time repeating multiple times
903      * at negative time zone offset transitions. For example, 1:30 AM on
904      * November 6, 2011 in US Eastern time (Ameirca/New_York) occurs twice;
905      * 1:30 AM EDT, then 1:30 AM EST one hour later. When <code>UCAL_WALLTIME_FIRST</code>
906      * is used, the wall time 1:30AM in this example will be interpreted as 1:30 AM EDT
907      * (first occurrence). When <code>UCAL_WALLTIME_LAST</code> is used, it will be
908      * interpreted as 1:30 AM EST (last occurrence). The default value is
909      * <code>UCAL_WALLTIME_LAST</code>.
910      * <p>
911      * <b>Note:</b>When <code>UCAL_WALLTIME_NEXT_VALID</code> is not a valid
912      * option for this. When the argument is neither <code>UCAL_WALLTIME_FIRST</code>
913      * nor <code>UCAL_WALLTIME_LAST</code>, this method has no effect and will keep
914      * the current setting.
915      *
916      * @param option the behavior for handling repeating wall time, either
917      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
918      * @see #getRepeatedWallTimeOption
919      * @stable ICU 49
920      */
921     void setRepeatedWallTimeOption(UCalendarWallTimeOption option);
922 
923     /**
924      * Gets the behavior for handling wall time repeating multiple times
925      * at negative time zone offset transitions.
926      *
927      * @return the behavior for handling repeating wall time, either
928      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
929      * @see #setRepeatedWallTimeOption
930      * @stable ICU 49
931      */
932     UCalendarWallTimeOption getRepeatedWallTimeOption(void) const;
933 
934     /**
935      * Sets the behavior for handling skipped wall time at positive time zone offset
936      * transitions. For example, 2:30 AM on March 13, 2011 in US Eastern time (America/New_York)
937      * does not exist because the wall time jump from 1:59 AM EST to 3:00 AM EDT. When
938      * <code>UCAL_WALLTIME_FIRST</code> is used, 2:30 AM is interpreted as 30 minutes before 3:00 AM
939      * EDT, therefore, it will be resolved as 1:30 AM EST. When <code>UCAL_WALLTIME_LAST</code>
940      * is used, 2:30 AM is interpreted as 31 minutes after 1:59 AM EST, therefore, it will be
941      * resolved as 3:30 AM EDT. When <code>UCAL_WALLTIME_NEXT_VALID</code> is used, 2:30 AM will
942      * be resolved as next valid wall time, that is 3:00 AM EDT. The default value is
943      * <code>UCAL_WALLTIME_LAST</code>.
944      * <p>
945      * <b>Note:</b>This option is effective only when this calendar is lenient.
946      * When the calendar is strict, such non-existing wall time will cause an error.
947      *
948      * @param option the behavior for handling skipped wall time at positive time zone
949      * offset transitions, one of <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code> and
950      * <code>UCAL_WALLTIME_NEXT_VALID</code>.
951      * @see #getSkippedWallTimeOption
952      *
953      * @stable ICU 49
954      */
955     void setSkippedWallTimeOption(UCalendarWallTimeOption option);
956 
957     /**
958      * Gets the behavior for handling skipped wall time at positive time zone offset
959      * transitions.
960      *
961      * @return the behavior for handling skipped wall time, one of
962      * <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code>
963      * and <code>UCAL_WALLTIME_NEXT_VALID</code>.
964      * @see #setSkippedWallTimeOption
965      * @stable ICU 49
966      */
967     UCalendarWallTimeOption getSkippedWallTimeOption(void) const;
968 
969 #ifndef U_HIDE_DEPRECATED_API
970     /**
971      * Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
972      *
973      * @param value  The given first day of the week.
974      * @deprecated ICU 2.6. Use setFirstDayOfWeek(UCalendarDaysOfWeek value) instead.
975      */
976     void setFirstDayOfWeek(EDaysOfWeek value);
977 #endif  /* U_HIDE_DEPRECATED_API */
978 
979     /**
980      * Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
981      *
982      * @param value  The given first day of the week.
983      * @stable ICU 2.6.
984      */
985     void setFirstDayOfWeek(UCalendarDaysOfWeek value);
986 
987 #ifndef U_HIDE_DEPRECATED_API
988     /**
989      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
990      *
991      * @return   The first day of the week.
992      * @deprecated ICU 2.6 use the overload with error code
993      */
994     EDaysOfWeek getFirstDayOfWeek(void) const;
995 #endif  /* U_HIDE_DEPRECATED_API */
996 
997     /**
998      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
999      *
1000      * @param status error code
1001      * @return   The first day of the week.
1002      * @stable ICU 2.6
1003      */
1004     UCalendarDaysOfWeek getFirstDayOfWeek(UErrorCode &status) const;
1005 
1006     /**
1007      * Sets what the minimal days required in the first week of the year are; For
1008      * example, if the first week is defined as one that contains the first day of the
1009      * first month of a year, call the method with value 1. If it must be a full week,
1010      * use value 7.
1011      *
1012      * @param value  The given minimal days required in the first week of the year.
1013      * @stable ICU 2.0
1014      */
1015     void setMinimalDaysInFirstWeek(uint8_t value);
1016 
1017     /**
1018      * Gets what the minimal days required in the first week of the year are; e.g., if
1019      * the first week is defined as one that contains the first day of the first month
1020      * of a year, getMinimalDaysInFirstWeek returns 1. If the minimal days required must
1021      * be a full week, getMinimalDaysInFirstWeek returns 7.
1022      *
1023      * @return   The minimal days required in the first week of the year.
1024      * @stable ICU 2.0
1025      */
1026     uint8_t getMinimalDaysInFirstWeek(void) const;
1027 
1028     /**
1029      * Gets the minimum value for the given time field. e.g., for Gregorian
1030      * DAY_OF_MONTH, 1.
1031      *
1032      * @param field  The given time field.
1033      * @return       The minimum value for the given time field.
1034      * @deprecated ICU 2.6. Use getMinimum(UCalendarDateFields field) instead.
1035      */
1036     virtual int32_t getMinimum(EDateFields field) const;
1037 
1038     /**
1039      * Gets the minimum value for the given time field. e.g., for Gregorian
1040      * DAY_OF_MONTH, 1.
1041      *
1042      * @param field  The given time field.
1043      * @return       The minimum value for the given time field.
1044      * @stable ICU 2.6.
1045      */
1046     virtual int32_t getMinimum(UCalendarDateFields field) const;
1047 
1048     /**
1049      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1050      * 31.
1051      *
1052      * @param field  The given time field.
1053      * @return       The maximum value for the given time field.
1054      * @deprecated ICU 2.6. Use getMaximum(UCalendarDateFields field) instead.
1055      */
1056     virtual int32_t getMaximum(EDateFields field) const;
1057 
1058     /**
1059      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1060      * 31.
1061      *
1062      * @param field  The given time field.
1063      * @return       The maximum value for the given time field.
1064      * @stable ICU 2.6.
1065      */
1066     virtual int32_t getMaximum(UCalendarDateFields field) const;
1067 
1068     /**
1069      * Gets the highest minimum value for the given field if varies. Otherwise same as
1070      * getMinimum(). For Gregorian, no difference.
1071      *
1072      * @param field  The given time field.
1073      * @return       The highest minimum value for the given time field.
1074      * @deprecated ICU 2.6. Use getGreatestMinimum(UCalendarDateFields field) instead.
1075      */
1076     virtual int32_t getGreatestMinimum(EDateFields field) const;
1077 
1078     /**
1079      * Gets the highest minimum value for the given field if varies. Otherwise same as
1080      * getMinimum(). For Gregorian, no difference.
1081      *
1082      * @param field  The given time field.
1083      * @return       The highest minimum value for the given time field.
1084      * @stable ICU 2.6.
1085      */
1086     virtual int32_t getGreatestMinimum(UCalendarDateFields field) const;
1087 
1088     /**
1089      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1090      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1091      *
1092      * @param field  The given time field.
1093      * @return       The lowest maximum value for the given time field.
1094      * @deprecated ICU 2.6. Use getLeastMaximum(UCalendarDateFields field) instead.
1095      */
1096     virtual int32_t getLeastMaximum(EDateFields field) const;
1097 
1098     /**
1099      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1100      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1101      *
1102      * @param field  The given time field.
1103      * @return       The lowest maximum value for the given time field.
1104      * @stable ICU 2.6.
1105      */
1106     virtual int32_t getLeastMaximum(UCalendarDateFields field) const;
1107 
1108 #ifndef U_HIDE_DEPRECATED_API
1109     /**
1110      * Return the minimum value that this field could have, given the current date.
1111      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1112      *
1113      * The version of this function on Calendar uses an iterative algorithm to determine the
1114      * actual minimum value for the field.  There is almost always a more efficient way to
1115      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1116      * overrides this function with a more efficient implementation.
1117      *
1118      * @param field    the field to determine the minimum of
1119      * @param status   Fill-in parameter which receives the status of this operation.
1120      * @return         the minimum of the given field for the current date of this Calendar
1121      * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field, UErrorCode& status) instead.
1122      */
1123     int32_t getActualMinimum(EDateFields field, UErrorCode& status) const;
1124 #endif  /* U_HIDE_DEPRECATED_API */
1125 
1126     /**
1127      * Return the minimum value that this field could have, given the current date.
1128      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1129      *
1130      * The version of this function on Calendar uses an iterative algorithm to determine the
1131      * actual minimum value for the field.  There is almost always a more efficient way to
1132      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1133      * overrides this function with a more efficient implementation.
1134      *
1135      * @param field    the field to determine the minimum of
1136      * @param status   Fill-in parameter which receives the status of this operation.
1137      * @return         the minimum of the given field for the current date of this Calendar
1138      * @stable ICU 2.6.
1139      */
1140     virtual int32_t getActualMinimum(UCalendarDateFields field, UErrorCode& status) const;
1141 
1142 #ifndef U_HIDE_DEPRECATED_API
1143     /**
1144      * Return the maximum value that this field could have, given the current date.
1145      * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1146      * maximum would be 28; for "Feb 3, 1996" it s 29.  Similarly for a Hebrew calendar,
1147      * for some years the actual maximum for MONTH is 12, and for others 13.
1148      *
1149      * The version of this function on Calendar uses an iterative algorithm to determine the
1150      * actual maximum value for the field.  There is almost always a more efficient way to
1151      * accomplish this (in most cases, you can simply return getMaximum()).  GregorianCalendar
1152      * overrides this function with a more efficient implementation.
1153      *
1154      * @param field    the field to determine the maximum of
1155      * @param status   Fill-in parameter which receives the status of this operation.
1156      * @return         the maximum of the given field for the current date of this Calendar
1157      * @deprecated ICU 2.6. Use getActualMaximum(UCalendarDateFields field, UErrorCode& status) instead.
1158      */
1159     int32_t getActualMaximum(EDateFields field, UErrorCode& status) const;
1160 #endif  /* U_HIDE_DEPRECATED_API */
1161 
1162     /**
1163      * Return the maximum value that this field could have, given the current date.
1164      * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1165      * maximum would be 28; for "Feb 3, 1996" it s 29.  Similarly for a Hebrew calendar,
1166      * for some years the actual maximum for MONTH is 12, and for others 13.
1167      *
1168      * The version of this function on Calendar uses an iterative algorithm to determine the
1169      * actual maximum value for the field.  There is almost always a more efficient way to
1170      * accomplish this (in most cases, you can simply return getMaximum()).  GregorianCalendar
1171      * overrides this function with a more efficient implementation.
1172      *
1173      * @param field    the field to determine the maximum of
1174      * @param status   Fill-in parameter which receives the status of this operation.
1175      * @return         the maximum of the given field for the current date of this Calendar
1176      * @stable ICU 2.6.
1177      */
1178     virtual int32_t getActualMaximum(UCalendarDateFields field, UErrorCode& status) const;
1179 
1180 #ifndef U_HIDE_DEPRECATED_API
1181     /**
1182      * Gets the value for a given time field. Recalculate the current time field values
1183      * if the time value has been changed by a call to setTime(). Return zero for unset
1184      * fields if any fields have been explicitly set by a call to set(). To force a
1185      * recomputation of all fields regardless of the previous state, call complete().
1186      * This method is semantically const, but may alter the object in memory.
1187      *
1188      * @param field  The given time field.
1189      * @param status Fill-in parameter which receives the status of the operation.
1190      * @return       The value for the given time field, or zero if the field is unset,
1191      *               and set() has been called for any other field.
1192      * @deprecated ICU 2.6. Use get(UCalendarDateFields field, UErrorCode& status) instead.
1193      */
1194     int32_t get(EDateFields field, UErrorCode& status) const;
1195 #endif  /* U_HIDE_DEPRECATED_API */
1196 
1197     /**
1198      * Gets the value for a given time field. Recalculate the current time field values
1199      * if the time value has been changed by a call to setTime(). Return zero for unset
1200      * fields if any fields have been explicitly set by a call to set(). To force a
1201      * recomputation of all fields regardless of the previous state, call complete().
1202      * This method is semantically const, but may alter the object in memory.
1203      *
1204      * @param field  The given time field.
1205      * @param status Fill-in parameter which receives the status of the operation.
1206      * @return       The value for the given time field, or zero if the field is unset,
1207      *               and set() has been called for any other field.
1208      * @stable ICU 2.6.
1209      */
1210     int32_t get(UCalendarDateFields field, UErrorCode& status) const;
1211 
1212 #ifndef U_HIDE_DEPRECATED_API
1213     /**
1214      * Determines if the given time field has a value set. This can affect in the
1215      * resolving of time in Calendar. Unset fields have a value of zero, by definition.
1216      *
1217      * @param field  The given time field.
1218      * @return   True if the given time field has a value set; false otherwise.
1219      * @deprecated ICU 2.6. Use isSet(UCalendarDateFields field) instead.
1220      */
1221     UBool isSet(EDateFields field) const;
1222 #endif  /* U_HIDE_DEPRECATED_API */
1223 
1224     /**
1225      * Determines if the given time field has a value set. This can affect in the
1226      * resolving of time in Calendar. Unset fields have a value of zero, by definition.
1227      *
1228      * @param field  The given time field.
1229      * @return   True if the given time field has a value set; false otherwise.
1230      * @stable ICU 2.6.
1231      */
1232     UBool isSet(UCalendarDateFields field) const;
1233 
1234 #ifndef U_HIDE_DEPRECATED_API
1235     /**
1236      * Sets the given time field with the given value.
1237      *
1238      * @param field  The given time field.
1239      * @param value  The value to be set for the given time field.
1240      * @deprecated ICU 2.6. Use set(UCalendarDateFields field, int32_t value) instead.
1241      */
1242     void set(EDateFields field, int32_t value);
1243 #endif  /* U_HIDE_DEPRECATED_API */
1244 
1245     /**
1246      * Sets the given time field with the given value.
1247      *
1248      * @param field  The given time field.
1249      * @param value  The value to be set for the given time field.
1250      * @stable ICU 2.6.
1251      */
1252     void set(UCalendarDateFields field, int32_t value);
1253 
1254     /**
1255      * Sets the values for the fields YEAR, MONTH, and DATE. Other field values are
1256      * retained; call clear() first if this is not desired.
1257      *
1258      * @param year   The value used to set the YEAR time field.
1259      * @param month  The value used to set the MONTH time field. Month value is 0-based.
1260      *               e.g., 0 for January.
1261      * @param date   The value used to set the DATE time field.
1262      * @stable ICU 2.0
1263      */
1264     void set(int32_t year, int32_t month, int32_t date);
1265 
1266     /**
1267      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, and MINUTE. Other
1268      * field values are retained; call clear() first if this is not desired.
1269      *
1270      * @param year    The value used to set the YEAR time field.
1271      * @param month   The value used to set the MONTH time field. Month value is
1272      *                0-based. E.g., 0 for January.
1273      * @param date    The value used to set the DATE time field.
1274      * @param hour    The value used to set the HOUR_OF_DAY time field.
1275      * @param minute  The value used to set the MINUTE time field.
1276      * @stable ICU 2.0
1277      */
1278     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute);
1279 
1280     /**
1281      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, MINUTE, and SECOND.
1282      * Other field values are retained; call clear() first if this is not desired.
1283      *
1284      * @param year    The value used to set the YEAR time field.
1285      * @param month   The value used to set the MONTH time field. Month value is
1286      *                0-based. E.g., 0 for January.
1287      * @param date    The value used to set the DATE time field.
1288      * @param hour    The value used to set the HOUR_OF_DAY time field.
1289      * @param minute  The value used to set the MINUTE time field.
1290      * @param second  The value used to set the SECOND time field.
1291      * @stable ICU 2.0
1292      */
1293     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, int32_t second);
1294 
1295     /**
1296      * Clears the values of all the time fields, making them both unset and assigning
1297      * them a value of zero. The field values will be determined during the next
1298      * resolving of time into time fields.
1299      * @stable ICU 2.0
1300      */
1301     void clear(void);
1302 
1303 #ifndef U_HIDE_DEPRECATED_API
1304     /**
1305      * Clears the value in the given time field, both making it unset and assigning it a
1306      * value of zero. This field value will be determined during the next resolving of
1307      * time into time fields.
1308      *
1309      * @param field  The time field to be cleared.
1310      * @deprecated ICU 2.6. Use clear(UCalendarDateFields field) instead.
1311      */
1312     void clear(EDateFields field);
1313 #endif  /* U_HIDE_DEPRECATED_API */
1314 
1315     /**
1316      * Clears the value in the given time field, both making it unset and assigning it a
1317      * value of zero. This field value will be determined during the next resolving of
1318      * time into time fields.
1319      *
1320      * @param field  The time field to be cleared.
1321      * @stable ICU 2.6.
1322      */
1323     void clear(UCalendarDateFields field);
1324 
1325     /**
1326      * Returns a unique class ID POLYMORPHICALLY. Pure virtual method. This method is to
1327      * implement a simple version of RTTI, since not all C++ compilers support genuine
1328      * RTTI. Polymorphic operator==() and clone() methods call this method.
1329      * <P>
1330      * Concrete subclasses of Calendar must implement getDynamicClassID() and also a
1331      * static method and data member:
1332      *
1333      *      static UClassID getStaticClassID() { return (UClassID)&amp;fgClassID; }
1334      *      static char fgClassID;
1335      *
1336      * @return   The class ID for this object. All objects of a given class have the
1337      *           same class ID. Objects of other classes have different class IDs.
1338      * @stable ICU 2.0
1339      */
1340     virtual UClassID getDynamicClassID(void) const = 0;
1341 
1342     /**
1343      * Returns the calendar type name string for this Calendar object.
1344      * The returned string is the legacy ICU calendar attribute value,
1345      * for example, "gregorian" or "japanese".
1346      *
1347      * See type="old type name" for the calendar attribute of locale IDs
1348      * at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
1349      *
1350      * Sample code for getting the LDML/BCP 47 calendar key value:
1351      * \code
1352      * const char *calType = cal->getType();
1353      * if (0 == strcmp(calType, "unknown")) {
1354      *     // deal with unknown calendar type
1355      * } else {
1356      *     string localeID("root@calendar=");
1357      *     localeID.append(calType);
1358      *     char langTag[100];
1359      *     UErrorCode errorCode = U_ZERO_ERROR;
1360      *     int32_t length = uloc_toLanguageTag(localeID.c_str(), langTag, (int32_t)sizeof(langTag), TRUE, &errorCode);
1361      *     if (U_FAILURE(errorCode)) {
1362      *         // deal with errors & overflow
1363      *     }
1364      *     string lang(langTag, length);
1365      *     size_t caPos = lang.find("-ca-");
1366      *     lang.erase(0, caPos + 4);
1367      *     // lang now contains the LDML calendar type
1368      * }
1369      * \endcode
1370      *
1371      * @return legacy calendar type name string
1372      * @stable ICU 49
1373      */
1374     virtual const char * getType() const = 0;
1375 
1376     /**
1377      * Returns whether the given day of the week is a weekday, a weekend day,
1378      * or a day that transitions from one to the other, for the locale and
1379      * calendar system associated with this Calendar (the locale's region is
1380      * often the most determinant factor). If a transition occurs at midnight,
1381      * then the days before and after the transition will have the
1382      * type UCAL_WEEKDAY or UCAL_WEEKEND. If a transition occurs at a time
1383      * other than midnight, then the day of the transition will have
1384      * the type UCAL_WEEKEND_ONSET or UCAL_WEEKEND_CEASE. In this case, the
1385      * method getWeekendTransition() will return the point of
1386      * transition.
1387      * @param dayOfWeek The day of the week whose type is desired (UCAL_SUNDAY..UCAL_SATURDAY).
1388      * @param status The error code for the operation.
1389      * @return The UCalendarWeekdayType for the day of the week.
1390      * @stable ICU 4.4
1391      */
1392     virtual UCalendarWeekdayType getDayOfWeekType(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1393 
1394     /**
1395      * Returns the time during the day at which the weekend begins or ends in
1396      * this calendar system.  If getDayOfWeekType() returns UCAL_WEEKEND_ONSET
1397      * for the specified dayOfWeek, return the time at which the weekend begins.
1398      * If getDayOfWeekType() returns UCAL_WEEKEND_CEASE for the specified dayOfWeek,
1399      * return the time at which the weekend ends. If getDayOfWeekType() returns
1400      * some other UCalendarWeekdayType for the specified dayOfWeek, is it an error condition
1401      * (U_ILLEGAL_ARGUMENT_ERROR).
1402      * @param dayOfWeek The day of the week for which the weekend transition time is
1403      * desired (UCAL_SUNDAY..UCAL_SATURDAY).
1404      * @param status The error code for the operation.
1405      * @return The milliseconds after midnight at which the weekend begins or ends.
1406      * @stable ICU 4.4
1407      */
1408     virtual int32_t getWeekendTransition(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1409 
1410     /**
1411      * Returns TRUE if the given UDate is in the weekend in
1412      * this calendar system.
1413      * @param date The UDate in question.
1414      * @param status The error code for the operation.
1415      * @return TRUE if the given UDate is in the weekend in
1416      * this calendar system, FALSE otherwise.
1417      * @stable ICU 4.4
1418      */
1419     virtual UBool isWeekend(UDate date, UErrorCode &status) const;
1420 
1421     /**
1422      * Returns TRUE if this Calendar's current date-time is in the weekend in
1423      * this calendar system.
1424      * @return TRUE if this Calendar's current date-time is in the weekend in
1425      * this calendar system, FALSE otherwise.
1426      * @stable ICU 4.4
1427      */
1428     virtual UBool isWeekend(void) const;
1429 
1430 protected:
1431 
1432      /**
1433       * Constructs a Calendar with the default time zone as returned by
1434       * TimeZone::createInstance(), and the default locale.
1435       *
1436       * @param success  Indicates the status of Calendar object construction. Returns
1437       *                 U_ZERO_ERROR if constructed successfully.
1438      * @stable ICU 2.0
1439       */
1440     Calendar(UErrorCode& success);
1441 
1442     /**
1443      * Copy constructor
1444      *
1445      * @param source    Calendar object to be copied from
1446      * @stable ICU 2.0
1447      */
1448     Calendar(const Calendar& source);
1449 
1450     /**
1451      * Default assignment operator
1452      *
1453      * @param right    Calendar object to be copied
1454      * @stable ICU 2.0
1455      */
1456     Calendar& operator=(const Calendar& right);
1457 
1458     /**
1459      * Constructs a Calendar with the given time zone and locale. Clients are no longer
1460      * responsible for deleting the given time zone object after it's adopted.
1461      *
1462      * @param zone     The given time zone.
1463      * @param aLocale  The given locale.
1464      * @param success  Indicates the status of Calendar object construction. Returns
1465      *                 U_ZERO_ERROR if constructed successfully.
1466      * @stable ICU 2.0
1467      */
1468     Calendar(TimeZone* zone, const Locale& aLocale, UErrorCode& success);
1469 
1470     /**
1471      * Constructs a Calendar with the given time zone and locale.
1472      *
1473      * @param zone     The given time zone.
1474      * @param aLocale  The given locale.
1475      * @param success  Indicates the status of Calendar object construction. Returns
1476      *                 U_ZERO_ERROR if constructed successfully.
1477      * @stable ICU 2.0
1478      */
1479     Calendar(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
1480 
1481     /**
1482      * Converts Calendar's time field values to GMT as milliseconds.
1483      *
1484      * @param status  Output param set to success/failure code on exit. If any value
1485      *                previously set in the time field is invalid or restricted by
1486      *                leniency, this will be set to an error status.
1487      * @stable ICU 2.0
1488      */
1489     virtual void computeTime(UErrorCode& status);
1490 
1491     /**
1492      * Converts GMT as milliseconds to time field values. This allows you to sync up the
1493      * time field values with a new time that is set for the calendar.  This method
1494      * does NOT recompute the time first; to recompute the time, then the fields, use
1495      * the method complete().
1496      *
1497      * @param status  Output param set to success/failure code on exit. If any value
1498      *                previously set in the time field is invalid or restricted by
1499      *                leniency, this will be set to an error status.
1500      * @stable ICU 2.0
1501      */
1502     virtual void computeFields(UErrorCode& status);
1503 
1504     /**
1505      * Gets this Calendar's current time as a long.
1506      *
1507      * @param status  Output param set to success/failure code on exit. If any value
1508      *                previously set in the time field is invalid or restricted by
1509      *                leniency, this will be set to an error status.
1510      * @return the current time as UTC milliseconds from the epoch.
1511      * @stable ICU 2.0
1512      */
1513     double getTimeInMillis(UErrorCode& status) const;
1514 
1515     /**
1516      * Sets this Calendar's current time from the given long value.
1517      * @param millis  the new time in UTC milliseconds from the epoch.
1518      * @param status  Output param set to success/failure code on exit. If any value
1519      *                previously set in the time field is invalid or restricted by
1520      *                leniency, this will be set to an error status.
1521      * @stable ICU 2.0
1522      */
1523     void setTimeInMillis( double millis, UErrorCode& status );
1524 
1525     /**
1526      * Recomputes the current time from currently set fields, and then fills in any
1527      * unset fields in the time field list.
1528      *
1529      * @param status  Output param set to success/failure code on exit. If any value
1530      *                previously set in the time field is invalid or restricted by
1531      *                leniency, this will be set to an error status.
1532      * @stable ICU 2.0
1533      */
1534     void complete(UErrorCode& status);
1535 
1536 #ifndef U_HIDE_DEPRECATED_API
1537     /**
1538      * Gets the value for a given time field. Subclasses can use this function to get
1539      * field values without forcing recomputation of time.
1540      *
1541      * @param field  The given time field.
1542      * @return       The value for the given time field.
1543      * @deprecated ICU 2.6. Use internalGet(UCalendarDateFields field) instead.
1544      */
internalGet(EDateFields field)1545     inline int32_t internalGet(EDateFields field) const {return fFields[field];}
1546 #endif  /* U_HIDE_DEPRECATED_API */
1547 
1548 #ifndef U_HIDE_INTERNAL_API
1549     /**
1550      * Gets the value for a given time field. Subclasses can use this function to get
1551      * field values without forcing recomputation of time. If the field's stamp is UNSET,
1552      * the defaultValue is used.
1553      *
1554      * @param field  The given time field.
1555      * @param defaultValue a default value used if the field is unset.
1556      * @return       The value for the given time field.
1557      * @internal
1558      */
internalGet(UCalendarDateFields field,int32_t defaultValue)1559     inline int32_t internalGet(UCalendarDateFields field, int32_t defaultValue) const {return fStamp[field]>kUnset ? fFields[field] : defaultValue;}
1560 
1561     /**
1562      * Gets the value for a given time field. Subclasses can use this function to get
1563      * field values without forcing recomputation of time.
1564      *
1565      * @param field  The given time field.
1566      * @return       The value for the given time field.
1567      * @internal
1568      */
internalGet(UCalendarDateFields field)1569     inline int32_t internalGet(UCalendarDateFields field) const {return fFields[field];}
1570 #endif  /* U_HIDE_INTERNAL_API */
1571 
1572 #ifndef U_HIDE_DEPRECATED_API
1573     /**
1574      * Sets the value for a given time field.  This is a fast internal method for
1575      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1576      * flags.
1577      *
1578      * @param field    The given time field.
1579      * @param value    The value for the given time field.
1580      * @deprecated ICU 2.6. Use internalSet(UCalendarDateFields field, int32_t value) instead.
1581      */
1582     void internalSet(EDateFields field, int32_t value);
1583 #endif  /* U_HIDE_DEPRECATED_API */
1584 
1585     /**
1586      * Sets the value for a given time field.  This is a fast internal method for
1587      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1588      * flags.
1589      *
1590      * @param field    The given time field.
1591      * @param value    The value for the given time field.
1592      * @stable ICU 2.6.
1593      */
1594     inline void internalSet(UCalendarDateFields field, int32_t value);
1595 
1596     /**
1597      * Prepare this calendar for computing the actual minimum or maximum.
1598      * This method modifies this calendar's fields; it is called on a
1599      * temporary calendar.
1600      * @internal
1601      */
1602     virtual void prepareGetActual(UCalendarDateFields field, UBool isMinimum, UErrorCode &status);
1603 
1604     /**
1605      * Limit enums. Not in sync with UCalendarLimitType (refers to internal fields).
1606      * @internal
1607      */
1608     enum ELimitType {
1609 #ifndef U_HIDE_INTERNAL_API
1610       UCAL_LIMIT_MINIMUM = 0,
1611       UCAL_LIMIT_GREATEST_MINIMUM,
1612       UCAL_LIMIT_LEAST_MAXIMUM,
1613       UCAL_LIMIT_MAXIMUM,
1614       UCAL_LIMIT_COUNT
1615 #endif  /* U_HIDE_INTERNAL_API */
1616     };
1617 
1618     /**
1619      * Subclass API for defining limits of different types.
1620      * Subclasses must implement this method to return limits for the
1621      * following fields:
1622      *
1623      * <pre>UCAL_ERA
1624      * UCAL_YEAR
1625      * UCAL_MONTH
1626      * UCAL_WEEK_OF_YEAR
1627      * UCAL_WEEK_OF_MONTH
1628      * UCAL_DATE (DAY_OF_MONTH on Java)
1629      * UCAL_DAY_OF_YEAR
1630      * UCAL_DAY_OF_WEEK_IN_MONTH
1631      * UCAL_YEAR_WOY
1632      * UCAL_EXTENDED_YEAR</pre>
1633      *
1634      * @param field one of the above field numbers
1635      * @param limitType one of <code>MINIMUM</code>, <code>GREATEST_MINIMUM</code>,
1636      * <code>LEAST_MAXIMUM</code>, or <code>MAXIMUM</code>
1637      * @internal
1638      */
1639     virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const = 0;
1640 
1641     /**
1642      * Return a limit for a field.
1643      * @param field the field, from <code>0..UCAL_MAX_FIELD</code>
1644      * @param limitType the type specifier for the limit
1645      * @see #ELimitType
1646      * @internal
1647      */
1648     virtual int32_t getLimit(UCalendarDateFields field, ELimitType limitType) const;
1649 
1650 
1651     /**
1652      * Return the Julian day number of day before the first day of the
1653      * given month in the given extended year.  Subclasses should override
1654      * this method to implement their calendar system.
1655      * @param eyear the extended year
1656      * @param month the zero-based month, or 0 if useMonth is false
1657      * @param useMonth if false, compute the day before the first day of
1658      * the given year, otherwise, compute the day before the first day of
1659      * the given month
1660      * @return the Julian day number of the day before the first
1661      * day of the given month and year
1662      * @internal
1663      */
1664     virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month,
1665                                                    UBool useMonth) const  = 0;
1666 
1667     /**
1668      * Return the number of days in the given month of the given extended
1669      * year of this calendar system.  Subclasses should override this
1670      * method if they can provide a more correct or more efficient
1671      * implementation than the default implementation in Calendar.
1672      * @internal
1673      */
1674     virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const ;
1675 
1676     /**
1677      * Return the number of days in the given extended year of this
1678      * calendar system.  Subclasses should override this method if they can
1679      * provide a more correct or more efficient implementation than the
1680      * default implementation in Calendar.
1681      * @stable ICU 2.0
1682      */
1683     virtual int32_t handleGetYearLength(int32_t eyear) const;
1684 
1685 
1686     /**
1687      * Return the extended year defined by the current fields.  This will
1688      * use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such
1689      * as UCAL_ERA) specific to the calendar system, depending on which set of
1690      * fields is newer.
1691      * @return the extended year
1692      * @internal
1693      */
1694     virtual int32_t handleGetExtendedYear() = 0;
1695 
1696     /**
1697      * Subclasses may override this.  This method calls
1698      * handleGetMonthLength() to obtain the calendar-specific month
1699      * length.
1700      * @param bestField which field to use to calculate the date
1701      * @return julian day specified by calendar fields.
1702      * @internal
1703      */
1704     virtual int32_t handleComputeJulianDay(UCalendarDateFields bestField);
1705 
1706     /**
1707      * Subclasses must override this to convert from week fields
1708      * (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case
1709      * where YEAR, EXTENDED_YEAR are not set.
1710      * The Calendar implementation assumes yearWoy is in extended gregorian form
1711      * @return the extended year, UCAL_EXTENDED_YEAR
1712      * @internal
1713      */
1714     virtual int32_t handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy);
1715 
1716     /**
1717      * Validate a single field of this calendar.  Subclasses should
1718      * override this method to validate any calendar-specific fields.
1719      * Generic fields can be handled by
1720      * <code>Calendar::validateField()</code>.
1721      * @see #validateField(int, int, int, int&)
1722      * @internal
1723      */
1724     virtual void validateField(UCalendarDateFields field, UErrorCode &status);
1725 
1726 #ifndef U_HIDE_INTERNAL_API
1727     /**
1728      * Compute the Julian day from fields.  Will determine whether to use
1729      * the JULIAN_DAY field directly, or other fields.
1730      * @return the julian day
1731      * @internal
1732      */
1733     int32_t computeJulianDay();
1734 
1735     /**
1736      * Compute the milliseconds in the day from the fields.  This is a
1737      * value from 0 to 23:59:59.999 inclusive, unless fields are out of
1738      * range, in which case it can be an arbitrary value.  This value
1739      * reflects local zone wall time.
1740      * @internal
1741      */
1742     int32_t computeMillisInDay();
1743 
1744     /**
1745      * This method can assume EXTENDED_YEAR has been set.
1746      * @param millis milliseconds of the date fields
1747      * @param millisInDay milliseconds of the time fields; may be out
1748      * or range.
1749      * @param ec Output param set to failure code on function return
1750      *          when this function fails.
1751      * @internal
1752      */
1753     int32_t computeZoneOffset(double millis, int32_t millisInDay, UErrorCode &ec);
1754 
1755 
1756     /**
1757      * Determine the best stamp in a range.
1758      * @param start first enum to look at
1759      * @param end last enum to look at
1760      * @param bestSoFar stamp prior to function call
1761      * @return the stamp value of the best stamp
1762      * @internal
1763      */
1764     int32_t newestStamp(UCalendarDateFields start, UCalendarDateFields end, int32_t bestSoFar) const;
1765 
1766     /**
1767      * Values for field resolution tables
1768      * @see #resolveFields
1769      * @internal
1770      */
1771     enum {
1772       /** Marker for end of resolve set (row or group). */
1773       kResolveSTOP = -1,
1774       /** Value to be bitwised "ORed" against resolve table field values for remapping.  Example: (UCAL_DATE | kResolveRemap) in 1st column will cause 'UCAL_DATE' to be returned, but will not examine the value of UCAL_DATE.  */
1775       kResolveRemap = 32
1776     };
1777 
1778     /**
1779      * Precedence table for Dates
1780      * @see #resolveFields
1781      * @internal
1782      */
1783     static const UFieldResolutionTable kDatePrecedence[];
1784 
1785     /**
1786      * Precedence table for Year
1787      * @see #resolveFields
1788      * @internal
1789      */
1790     static const UFieldResolutionTable kYearPrecedence[];
1791 
1792     /**
1793      * Precedence table for Day of Week
1794      * @see #resolveFields
1795      * @internal
1796      */
1797     static const UFieldResolutionTable kDOWPrecedence[];
1798 
1799     /**
1800      * Given a precedence table, return the newest field combination in
1801      * the table, or UCAL_FIELD_COUNT if none is found.
1802      *
1803      * <p>The precedence table is a 3-dimensional array of integers.  It
1804      * may be thought of as an array of groups.  Each group is an array of
1805      * lines.  Each line is an array of field numbers.  Within a line, if
1806      * all fields are set, then the time stamp of the line is taken to be
1807      * the stamp of the most recently set field.  If any field of a line is
1808      * unset, then the line fails to match.  Within a group, the line with
1809      * the newest time stamp is selected.  The first field of the line is
1810      * returned to indicate which line matched.
1811      *
1812      * <p>In some cases, it may be desirable to map a line to field that
1813      * whose stamp is NOT examined.  For example, if the best field is
1814      * DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used.  In
1815      * order to do this, insert the value <code>kResolveRemap | F</code> at
1816      * the start of the line, where <code>F</code> is the desired return
1817      * field value.  This field will NOT be examined; it only determines
1818      * the return value if the other fields in the line are the newest.
1819      *
1820      * <p>If all lines of a group contain at least one unset field, then no
1821      * line will match, and the group as a whole will fail to match.  In
1822      * that case, the next group will be processed.  If all groups fail to
1823      * match, then UCAL_FIELD_COUNT is returned.
1824      * @internal
1825      */
1826     UCalendarDateFields resolveFields(const UFieldResolutionTable *precedenceTable);
1827 #endif  /* U_HIDE_INTERNAL_API */
1828 
1829 
1830     /**
1831      * @internal
1832      */
1833     virtual const UFieldResolutionTable* getFieldResolutionTable() const;
1834 
1835 #ifndef U_HIDE_INTERNAL_API
1836     /**
1837      * Return the field that is newer, either defaultField, or
1838      * alternateField.  If neither is newer or neither is set, return defaultField.
1839      * @internal
1840      */
1841     UCalendarDateFields newerField(UCalendarDateFields defaultField, UCalendarDateFields alternateField) const;
1842 #endif  /* U_HIDE_INTERNAL_API */
1843 
1844 
1845 private:
1846     /**
1847      * Helper function for calculating limits by trial and error
1848      * @param field The field being investigated
1849      * @param startValue starting (least max) value of field
1850      * @param endValue ending (greatest max) value of field
1851      * @param status return type
1852      * @internal
1853      */
1854     int32_t getActualHelper(UCalendarDateFields field, int32_t startValue, int32_t endValue, UErrorCode &status) const;
1855 
1856 
1857 protected:
1858     /**
1859      * The flag which indicates if the current time is set in the calendar.
1860      * @stable ICU 2.0
1861      */
1862     UBool      fIsTimeSet;
1863 
1864     /**
1865      * True if the fields are in sync with the currently set time of this Calendar.
1866      * If false, then the next attempt to get the value of a field will
1867      * force a recomputation of all fields from the current value of the time
1868      * field.
1869      * <P>
1870      * This should really be named areFieldsInSync, but the old name is retained
1871      * for backward compatibility.
1872      * @stable ICU 2.0
1873      */
1874     UBool      fAreFieldsSet;
1875 
1876     /**
1877      * True if all of the fields have been set.  This is initially false, and set to
1878      * true by computeFields().
1879      * @stable ICU 2.0
1880      */
1881     UBool      fAreAllFieldsSet;
1882 
1883     /**
1884      * True if all fields have been virtually set, but have not yet been
1885      * computed.  This occurs only in setTimeInMillis().  A calendar set
1886      * to this state will compute all fields from the time if it becomes
1887      * necessary, but otherwise will delay such computation.
1888      * @stable ICU 3.0
1889      */
1890     UBool fAreFieldsVirtuallySet;
1891 
1892     /**
1893      * Get the current time without recomputing.
1894      *
1895      * @return     the current time without recomputing.
1896      * @stable ICU 2.0
1897      */
internalGetTime(void)1898     UDate        internalGetTime(void) const     { return fTime; }
1899 
1900     /**
1901      * Set the current time without affecting flags or fields.
1902      *
1903      * @param time    The time to be set
1904      * @return        the current time without recomputing.
1905      * @stable ICU 2.0
1906      */
internalSetTime(UDate time)1907     void        internalSetTime(UDate time)     { fTime = time; }
1908 
1909     /**
1910      * The time fields containing values into which the millis is computed.
1911      * @stable ICU 2.0
1912      */
1913     int32_t     fFields[UCAL_FIELD_COUNT];
1914 
1915     /**
1916      * The flags which tell if a specified time field for the calendar is set.
1917      * @deprecated ICU 2.8 use (fStamp[n]!=kUnset)
1918      */
1919     UBool      fIsSet[UCAL_FIELD_COUNT];
1920 
1921     /** Special values of stamp[]
1922      * @stable ICU 2.0
1923      */
1924     enum {
1925         kUnset                 = 0,
1926         kInternallySet,
1927         kMinimumUserStamp
1928     };
1929 
1930     /**
1931      * Pseudo-time-stamps which specify when each field was set. There
1932      * are two special values, UNSET and INTERNALLY_SET. Values from
1933      * MINIMUM_USER_SET to Integer.MAX_VALUE are legal user set values.
1934      * @stable ICU 2.0
1935      */
1936     int32_t        fStamp[UCAL_FIELD_COUNT];
1937 
1938     /**
1939      * Subclasses may override this method to compute several fields
1940      * specific to each calendar system.  These are:
1941      *
1942      * <ul><li>ERA
1943      * <li>YEAR
1944      * <li>MONTH
1945      * <li>DAY_OF_MONTH
1946      * <li>DAY_OF_YEAR
1947      * <li>EXTENDED_YEAR</ul>
1948      *
1949      * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which
1950      * will be set when this method is called.  Subclasses can also call
1951      * the getGregorianXxx() methods to obtain Gregorian calendar
1952      * equivalents for the given Julian day.
1953      *
1954      * <p>In addition, subclasses should compute any subclass-specific
1955      * fields, that is, fields from BASE_FIELD_COUNT to
1956      * getFieldCount() - 1.
1957      *
1958      * <p>The default implementation in <code>Calendar</code> implements
1959      * a pure proleptic Gregorian calendar.
1960      * @internal
1961      */
1962     virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
1963 
1964 #ifndef U_HIDE_INTERNAL_API
1965     /**
1966      * Return the extended year on the Gregorian calendar as computed by
1967      * <code>computeGregorianFields()</code>.
1968      * @internal
1969      */
getGregorianYear()1970     int32_t getGregorianYear() const {
1971         return fGregorianYear;
1972     }
1973 
1974     /**
1975      * Return the month (0-based) on the Gregorian calendar as computed by
1976      * <code>computeGregorianFields()</code>.
1977      * @internal
1978      */
getGregorianMonth()1979     int32_t getGregorianMonth() const {
1980         return fGregorianMonth;
1981     }
1982 
1983     /**
1984      * Return the day of year (1-based) on the Gregorian calendar as
1985      * computed by <code>computeGregorianFields()</code>.
1986      * @internal
1987      */
getGregorianDayOfYear()1988     int32_t getGregorianDayOfYear() const {
1989         return fGregorianDayOfYear;
1990     }
1991 
1992     /**
1993      * Return the day of month (1-based) on the Gregorian calendar as
1994      * computed by <code>computeGregorianFields()</code>.
1995      * @internal
1996      */
getGregorianDayOfMonth()1997     int32_t getGregorianDayOfMonth() const {
1998       return fGregorianDayOfMonth;
1999     }
2000 #endif  /* U_HIDE_INTERNAL_API */
2001 
2002     /**
2003      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
2004      * taking year and era into account.  Defaults to 0 for Gregorian, which doesn't care.
2005      * @param eyear The extended year
2006      * @internal
2007      */
2008     virtual int32_t getDefaultMonthInYear(int32_t eyear) ;
2009 
2010 
2011     /**
2012      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
2013      * taking currently-set year and era into account.  Defaults to 1 for Gregorian.
2014      * @param eyear the extended year
2015      * @param month the month in the year
2016      * @internal
2017      */
2018     virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month);
2019 
2020     //-------------------------------------------------------------------------
2021     // Protected utility methods for use by subclasses.  These are very handy
2022     // for implementing add, roll, and computeFields.
2023     //-------------------------------------------------------------------------
2024 
2025     /**
2026      * Adjust the specified field so that it is within
2027      * the allowable range for the date to which this calendar is set.
2028      * For example, in a Gregorian calendar pinning the {@link #UCalendarDateFields DAY_OF_MONTH}
2029      * field for a calendar set to April 31 would cause it to be set
2030      * to April 30.
2031      * <p>
2032      * <b>Subclassing:</b>
2033      * <br>
2034      * This utility method is intended for use by subclasses that need to implement
2035      * their own overrides of {@link #roll roll} and {@link #add add}.
2036      * <p>
2037      * <b>Note:</b>
2038      * <code>pinField</code> is implemented in terms of
2039      * {@link #getActualMinimum getActualMinimum}
2040      * and {@link #getActualMaximum getActualMaximum}.  If either of those methods uses
2041      * a slow, iterative algorithm for a particular field, it would be
2042      * unwise to attempt to call <code>pinField</code> for that field.  If you
2043      * really do need to do so, you should override this method to do
2044      * something more efficient for that field.
2045      * <p>
2046      * @param field The calendar field whose value should be pinned.
2047      * @param status Output param set to failure code on function return
2048      *          when this function fails.
2049      *
2050      * @see #getActualMinimum
2051      * @see #getActualMaximum
2052      * @stable ICU 2.0
2053      */
2054     virtual void pinField(UCalendarDateFields field, UErrorCode& status);
2055 
2056     /**
2057      * Return the week number of a day, within a period. This may be the week number in
2058      * a year or the week number in a month. Usually this will be a value >= 1, but if
2059      * some initial days of the period are excluded from week 1, because
2060      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then
2061      * the week number will be zero for those
2062      * initial days. This method requires the day number and day of week for some
2063      * known date in the period in order to determine the day of week
2064      * on the desired day.
2065      * <p>
2066      * <b>Subclassing:</b>
2067      * <br>
2068      * This method is intended for use by subclasses in implementing their
2069      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
2070      * It is often useful in {@link #getActualMinimum getActualMinimum} and
2071      * {@link #getActualMaximum getActualMaximum} as well.
2072      * <p>
2073      * This variant is handy for computing the week number of some other
2074      * day of a period (often the first or last day of the period) when its day
2075      * of the week is not known but the day number and day of week for some other
2076      * day in the period (e.g. the current date) <em>is</em> known.
2077      * <p>
2078      * @param desiredDay    The {@link #UCalendarDateFields DAY_OF_YEAR} or
2079      *              {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2080      *              Should be 1 for the first day of the period.
2081      *
2082      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR}
2083      *              or {@link #UCalendarDateFields DAY_OF_MONTH} for a day in the period whose
2084      *              {@link #UCalendarDateFields DAY_OF_WEEK} is specified by the
2085      *              <code>knownDayOfWeek</code> parameter.
2086      *              Should be 1 for first day of period.
2087      *
2088      * @param dayOfWeek  The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2089      *              corresponding to the <code>knownDayOfPeriod</code> parameter.
2090      *              1-based with 1=Sunday.
2091      *
2092      * @return      The week number (one-based), or zero if the day falls before
2093      *              the first week because
2094      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2095      *              is more than one.
2096      *
2097      * @stable ICU 2.8
2098      */
2099     int32_t weekNumber(int32_t desiredDay, int32_t dayOfPeriod, int32_t dayOfWeek);
2100 
2101 
2102 #ifndef U_HIDE_INTERNAL_API
2103     /**
2104      * Return the week number of a day, within a period. This may be the week number in
2105      * a year, or the week number in a month. Usually this will be a value >= 1, but if
2106      * some initial days of the period are excluded from week 1, because
2107      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1,
2108      * then the week number will be zero for those
2109      * initial days. This method requires the day of week for the given date in order to
2110      * determine the result.
2111      * <p>
2112      * <b>Subclassing:</b>
2113      * <br>
2114      * This method is intended for use by subclasses in implementing their
2115      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
2116      * It is often useful in {@link #getActualMinimum getActualMinimum} and
2117      * {@link #getActualMaximum getActualMaximum} as well.
2118      * <p>
2119      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR} or
2120      *                      {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2121      *                      Should be 1 for the first day of the period.
2122      *
2123      * @param dayOfWeek     The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2124      *                      corresponding to the <code>dayOfPeriod</code> parameter.
2125      *                      1-based with 1=Sunday.
2126      *
2127      * @return      The week number (one-based), or zero if the day falls before
2128      *              the first week because
2129      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2130      *              is more than one.
2131      * @internal
2132      */
2133     inline int32_t weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek);
2134 
2135     /**
2136      * returns the local DOW, valid range 0..6
2137      * @internal
2138      */
2139     int32_t getLocalDOW();
2140 #endif  /* U_HIDE_INTERNAL_API */
2141 
2142 private:
2143 
2144     /**
2145      * The next available value for fStamp[]
2146      */
2147     int32_t fNextStamp;// = MINIMUM_USER_STAMP;
2148 
2149     /**
2150      * Recalculates the time stamp array (fStamp).
2151      * Resets fNextStamp to lowest next stamp value.
2152      */
2153     void recalculateStamp();
2154 
2155     /**
2156      * The current time set for the calendar.
2157      */
2158     UDate        fTime;
2159 
2160     /**
2161      * @see   #setLenient
2162      */
2163     UBool      fLenient;
2164 
2165     /**
2166      * Time zone affects the time calculation done by Calendar. Calendar subclasses use
2167      * the time zone data to produce the local time. Always set; never NULL.
2168      */
2169     TimeZone*   fZone;
2170 
2171     /**
2172      * Option for rpeated wall time
2173      * @see #setRepeatedWallTimeOption
2174      */
2175     UCalendarWallTimeOption fRepeatedWallTime;
2176 
2177     /**
2178      * Option for skipped wall time
2179      * @see #setSkippedWallTimeOption
2180      */
2181     UCalendarWallTimeOption fSkippedWallTime;
2182 
2183     /**
2184      * Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent. They are
2185      * used to figure out the week count for a specific date for a given locale. These
2186      * must be set when a Calendar is constructed. For example, in US locale,
2187      * firstDayOfWeek is SUNDAY; minimalDaysInFirstWeek is 1. They are used to figure
2188      * out the week count for a specific date for a given locale. These must be set when
2189      * a Calendar is constructed.
2190      */
2191     UCalendarDaysOfWeek fFirstDayOfWeek;
2192     uint8_t     fMinimalDaysInFirstWeek;
2193     UCalendarDaysOfWeek fWeekendOnset;
2194     int32_t fWeekendOnsetMillis;
2195     UCalendarDaysOfWeek fWeekendCease;
2196     int32_t fWeekendCeaseMillis;
2197 
2198     /**
2199      * Sets firstDayOfWeek and minimalDaysInFirstWeek. Called at Calendar construction
2200      * time.
2201      *
2202      * @param desiredLocale  The given locale.
2203      * @param type           The calendar type identifier, e.g: gregorian, buddhist, etc.
2204      * @param success        Indicates the status of setting the week count data from
2205      *                       the resource for the given locale. Returns U_ZERO_ERROR if
2206      *                       constructed successfully.
2207      */
2208     void        setWeekData(const Locale& desiredLocale, const char *type, UErrorCode& success);
2209 
2210     /**
2211      * Recompute the time and update the status fields isTimeSet
2212      * and areFieldsSet.  Callers should check isTimeSet and only
2213      * call this method if isTimeSet is false.
2214      *
2215      * @param status  Output param set to success/failure code on exit. If any value
2216      *                previously set in the time field is invalid or restricted by
2217      *                leniency, this will be set to an error status.
2218      */
2219     void updateTime(UErrorCode& status);
2220 
2221     /**
2222      * The Gregorian year, as computed by computeGregorianFields() and
2223      * returned by getGregorianYear().
2224      * @see #computeGregorianFields
2225      */
2226     int32_t fGregorianYear;
2227 
2228     /**
2229      * The Gregorian month, as computed by computeGregorianFields() and
2230      * returned by getGregorianMonth().
2231      * @see #computeGregorianFields
2232      */
2233     int32_t fGregorianMonth;
2234 
2235     /**
2236      * The Gregorian day of the year, as computed by
2237      * computeGregorianFields() and returned by getGregorianDayOfYear().
2238      * @see #computeGregorianFields
2239      */
2240     int32_t fGregorianDayOfYear;
2241 
2242     /**
2243      * The Gregorian day of the month, as computed by
2244      * computeGregorianFields() and returned by getGregorianDayOfMonth().
2245      * @see #computeGregorianFields
2246      */
2247     int32_t fGregorianDayOfMonth;
2248 
2249     /* calculations */
2250 
2251     /**
2252      * Compute the Gregorian calendar year, month, and day of month from
2253      * the given Julian day.  These values are not stored in fields, but in
2254      * member variables gregorianXxx.  Also compute the DAY_OF_WEEK and
2255      * DOW_LOCAL fields.
2256      */
2257     void computeGregorianAndDOWFields(int32_t julianDay, UErrorCode &ec);
2258 
2259 protected:
2260 
2261     /**
2262      * Compute the Gregorian calendar year, month, and day of month from the
2263      * Julian day.  These values are not stored in fields, but in member
2264      * variables gregorianXxx.  They are used for time zone computations and by
2265      * subclasses that are Gregorian derivatives.  Subclasses may call this
2266      * method to perform a Gregorian calendar millis->fields computation.
2267      */
2268     void computeGregorianFields(int32_t julianDay, UErrorCode &ec);
2269 
2270 private:
2271 
2272     /**
2273      * Compute the fields WEEK_OF_YEAR, YEAR_WOY, WEEK_OF_MONTH,
2274      * DAY_OF_WEEK_IN_MONTH, and DOW_LOCAL from EXTENDED_YEAR, YEAR,
2275      * DAY_OF_WEEK, and DAY_OF_YEAR.  The latter fields are computed by the
2276      * subclass based on the calendar system.
2277      *
2278      * <p>The YEAR_WOY field is computed simplistically.  It is equal to YEAR
2279      * most of the time, but at the year boundary it may be adjusted to YEAR-1
2280      * or YEAR+1 to reflect the overlap of a week into an adjacent year.  In
2281      * this case, a simple increment or decrement is performed on YEAR, even
2282      * though this may yield an invalid YEAR value.  For instance, if the YEAR
2283      * is part of a calendar system with an N-year cycle field CYCLE, then
2284      * incrementing the YEAR may involve incrementing CYCLE and setting YEAR
2285      * back to 0 or 1.  This is not handled by this code, and in fact cannot be
2286      * simply handled without having subclasses define an entire parallel set of
2287      * fields for fields larger than or equal to a year.  This additional
2288      * complexity is not warranted, since the intention of the YEAR_WOY field is
2289      * to support ISO 8601 notation, so it will typically be used with a
2290      * proleptic Gregorian calendar, which has no field larger than a year.
2291      */
2292     void computeWeekFields(UErrorCode &ec);
2293 
2294 
2295     /**
2296      * Ensure that each field is within its valid range by calling {@link
2297      * #validateField(int, int&)} on each field that has been set.  This method
2298      * should only be called if this calendar is not lenient.
2299      * @see #isLenient
2300      * @see #validateField(int, int&)
2301      * @internal
2302      */
2303     void validateFields(UErrorCode &status);
2304 
2305     /**
2306      * Validate a single field of this calendar given its minimum and
2307      * maximum allowed value.  If the field is out of range,
2308      * <code>U_ILLEGAL_ARGUMENT_ERROR</code> will be set.  Subclasses may
2309      * use this method in their implementation of {@link
2310      * #validateField(int, int&)}.
2311      * @internal
2312      */
2313     void validateField(UCalendarDateFields field, int32_t min, int32_t max, UErrorCode& status);
2314 
2315  protected:
2316 #ifndef U_HIDE_INTERNAL_API
2317     /**
2318      * Convert a quasi Julian date to the day of the week. The Julian date used here is
2319      * not a true Julian date, since it is measured from midnight, not noon. Return
2320      * value is one-based.
2321      *
2322      * @param julian  The given Julian date number.
2323      * @return   Day number from 1..7 (SUN..SAT).
2324      * @internal
2325      */
2326     static uint8_t julianDayToDayOfWeek(double julian);
2327 #endif  /* U_HIDE_INTERNAL_API */
2328 
2329  private:
2330     char validLocale[ULOC_FULLNAME_CAPACITY];
2331     char actualLocale[ULOC_FULLNAME_CAPACITY];
2332 
2333  public:
2334 #if !UCONFIG_NO_SERVICE
2335     /**
2336      * INTERNAL FOR 2.6 --  Registration.
2337      */
2338 
2339 #ifndef U_HIDE_INTERNAL_API
2340     /**
2341      * Return a StringEnumeration over the locales available at the time of the call,
2342      * including registered locales.
2343      * @return a StringEnumeration over the locales available at the time of the call
2344      * @internal
2345      */
2346     static StringEnumeration* getAvailableLocales(void);
2347 
2348     /**
2349      * Register a new Calendar factory.  The factory will be adopted.
2350      * INTERNAL in 2.6
2351      *
2352      * Because ICU may choose to cache Calendars internally, this must
2353      * be called at application startup, prior to any calls to
2354      * Calendar::createInstance to avoid undefined behavior.
2355      *
2356      * @param toAdopt the factory instance to be adopted
2357      * @param status the in/out status code, no special meanings are assigned
2358      * @return a registry key that can be used to unregister this factory
2359      * @internal
2360      */
2361     static URegistryKey registerFactory(ICUServiceFactory* toAdopt, UErrorCode& status);
2362 
2363     /**
2364      * Unregister a previously-registered CalendarFactory using the key returned from the
2365      * register call.  Key becomes invalid after a successful call and should not be used again.
2366      * The CalendarFactory corresponding to the key will be deleted.
2367      * INTERNAL in 2.6
2368      *
2369      * Because ICU may choose to cache Calendars internally, this should
2370      * be called during application shutdown, after all calls to
2371      * Calendar::createInstance to avoid undefined behavior.
2372      *
2373      * @param key the registry key returned by a previous call to registerFactory
2374      * @param status the in/out status code, no special meanings are assigned
2375      * @return TRUE if the factory for the key was successfully unregistered
2376      * @internal
2377      */
2378     static UBool unregister(URegistryKey key, UErrorCode& status);
2379 #endif  /* U_HIDE_INTERNAL_API */
2380 
2381     /**
2382      * Multiple Calendar Implementation
2383      * @internal
2384      */
2385     friend class CalendarFactory;
2386 
2387     /**
2388      * Multiple Calendar Implementation
2389      * @internal
2390      */
2391     friend class CalendarService;
2392 
2393     /**
2394      * Multiple Calendar Implementation
2395      * @internal
2396      */
2397     friend class DefaultCalendarFactory;
2398 #endif /* !UCONFIG_NO_SERVICE */
2399 
2400     /**
2401      * @return TRUE if this calendar has a default century (i.e. 03 -> 2003)
2402      * @internal
2403      */
2404     virtual UBool haveDefaultCentury() const = 0;
2405 
2406     /**
2407      * @return the start of the default century, as a UDate
2408      * @internal
2409      */
2410     virtual UDate defaultCenturyStart() const = 0;
2411     /**
2412      * @return the beginning year of the default century, as a year
2413      * @internal
2414      */
2415     virtual int32_t defaultCenturyStartYear() const = 0;
2416 
2417     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2418      *  @param type type of the locale we're looking for (valid or actual)
2419      *  @param status error code for the operation
2420      *  @return the locale
2421      *  @stable ICU 2.8
2422      */
2423     Locale getLocale(ULocDataLocaleType type, UErrorCode &status) const;
2424 
2425     /**
2426      * @return      The related Gregorian year; will be obtained by modifying the value
2427      *              obtained by get from UCAL_EXTENDED_YEAR field
2428      * @internal
2429      */
2430     virtual int32_t getRelatedYear(UErrorCode &status) const;
2431 
2432     /**
2433      * @param year  The related Gregorian year to set; will be modified as necessary then
2434      *              set in UCAL_EXTENDED_YEAR field
2435      * @internal
2436      */
2437     virtual void setRelatedYear(int32_t year);
2438 
2439 #ifndef U_HIDE_INTERNAL_API
2440     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2441      *  @param type type of the locale we're looking for (valid or actual)
2442      *  @param status error code for the operation
2443      *  @return the locale
2444      *  @internal
2445      */
2446     const char* getLocaleID(ULocDataLocaleType type, UErrorCode &status) const;
2447 #endif  /* U_HIDE_INTERNAL_API */
2448 
2449 private:
2450     /**
2451      * Cast TimeZone used by this object to BasicTimeZone, or NULL if the TimeZone
2452      * is not an instance of BasicTimeZone.
2453      */
2454     BasicTimeZone* getBasicTimeZone() const;
2455 
2456     /**
2457      * Find the previous zone transtion near the given time.
2458      * @param base The base time, inclusive
2459      * @param transitionTime Receives the result time
2460      * @param status The error status
2461      * @return TRUE if a transition is found.
2462      */
2463     UBool getImmediatePreviousZoneTransition(UDate base, UDate *transitionTime, UErrorCode& status) const;
2464 
2465 public:
2466 #ifndef U_HIDE_INTERNAL_API
2467     /**
2468      * Creates a new Calendar from a Locale for the cache.
2469      * This method does not set the time or timezone in returned calendar.
2470      * @param locale the locale.
2471      * @param status any error returned here.
2472      * @return the new Calendar object with no time or timezone set.
2473      * @internal For ICU use only.
2474      */
2475     static Calendar * U_EXPORT2 makeInstance(
2476             const Locale &locale, UErrorCode &status);
2477 
2478     /**
2479      * Get the calendar type for given locale.
2480      * @param locale the locale
2481      * @param typeBuffer calendar type returned here
2482      * @param typeBufferSize The size of typeBuffer in bytes. If the type
2483      *   can't fit in the buffer, this method sets status to
2484      *   U_BUFFER_OVERFLOW_ERROR
2485      * @param status error, if any, returned here.
2486      * @internal For ICU use only.
2487      */
2488     static void U_EXPORT2 getCalendarTypeFromLocale(
2489             const Locale &locale,
2490             char *typeBuffer,
2491             int32_t typeBufferSize,
2492             UErrorCode &status);
2493 #endif  /* U_HIDE_INTERNAL_API */
2494 };
2495 
2496 // -------------------------------------
2497 
2498 inline Calendar*
createInstance(TimeZone * zone,UErrorCode & errorCode)2499 Calendar::createInstance(TimeZone* zone, UErrorCode& errorCode)
2500 {
2501     // since the Locale isn't specified, use the default locale
2502     return createInstance(zone, Locale::getDefault(), errorCode);
2503 }
2504 
2505 // -------------------------------------
2506 
2507 inline void
roll(UCalendarDateFields field,UBool up,UErrorCode & status)2508 Calendar::roll(UCalendarDateFields field, UBool up, UErrorCode& status)
2509 {
2510     roll(field, (int32_t)(up ? +1 : -1), status);
2511 }
2512 
2513 #ifndef U_HIDE_DEPRECATED_API
2514 inline void
roll(EDateFields field,UBool up,UErrorCode & status)2515 Calendar::roll(EDateFields field, UBool up, UErrorCode& status)
2516 {
2517     roll((UCalendarDateFields) field, up, status);
2518 }
2519 #endif  /* U_HIDE_DEPRECATED_API */
2520 
2521 
2522 // -------------------------------------
2523 
2524 /**
2525  * Fast method for subclasses.  The caller must maintain fUserSetDSTOffset and
2526  * fUserSetZoneOffset, as well as the isSet[] array.
2527  */
2528 
2529 inline void
internalSet(UCalendarDateFields field,int32_t value)2530 Calendar::internalSet(UCalendarDateFields field, int32_t value)
2531 {
2532     fFields[field] = value;
2533     fStamp[field] = kInternallySet;
2534     fIsSet[field]     = TRUE; // Remove later
2535 }
2536 
2537 
2538 #ifndef U_HIDE_INTERNAL_API
weekNumber(int32_t dayOfPeriod,int32_t dayOfWeek)2539 inline int32_t  Calendar::weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek)
2540 {
2541   return weekNumber(dayOfPeriod, dayOfPeriod, dayOfWeek);
2542 }
2543 #endif  /* U_HIDE_INTERNAL_API */
2544 
2545 U_NAMESPACE_END
2546 
2547 #endif /* #if !UCONFIG_NO_FORMATTING */
2548 
2549 #endif // _CALENDAR
2550